Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-03T00:26:35.006Z Has data issue: false hasContentIssue false
  • English
  • Français

Studies on the mechanism of gel formation in the California mastitis test reaction*

Published online by Cambridge University Press:  01 June 2009

G. Nageswararao  and
J. B. Derbyshire
G. Nageswararao
Affiliation:
Department of Veterinary Science, University of Wisconsin, Madison, Wisconsin, U.S.A.
J. B. Derbyshire
Affiliation:
Department of Veterinary Science, University of Wisconsin, Madison, Wisconsin, U.S.A.
Get access Rights & Permissions [Opens in a new window]

Summary

The effects of various factors on gel formation in the California Mastitis Test (CMT) were studied to obtain information on the mechanism of the reaction. Death of the leucocytes in milk, produced either by storing the milk at 5°C or by freezing and thawing, markedly reduced the viscosity of the gel formed by the milk with CMT reagent. Samples of skim-milk to which leucocytes were added gave increasingly viscous gels with CMT reagent as the pH was increased to 10·0. Soluble casein increased the viscosity of the gel formed by leucocytes with CMT reagent. The viscosity of the gel was decreased by the addition of CaCl2 and NaCl. On microscopic examination the gel formed in the CMT appeared as an irregularly arranged fibrillar network containing DNA. Deoxyribonuclease I rapidly eliminated the gel-forming property of leucocyte nuclei with CMT reagent, and EDTA inhibited this enzyme activity. Crude protease, trypsin, papain and bacterial protease decreased the gelforming property to different degrees. The presence of EDTA with these enzymes resulted in the formation of a viscous, ropy gel before the addition of CMT reagent. It was concluded that at least a part of the protein of the DNA-protein complex of leucocyte nuclei, in addition to the native polymer of DNA, was necessary for gel formation in the CMT reaction.

Type
Original Articles
Information
Journal of Dairy Research , Volume 36 , Issue 3 , October 1969 , pp. 359 - 368
Copyright
Copyright © Proprietors of Journal of Dairy Research 1969

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bernstein, M. H. (1956). Proc. natn. Acad. Sci. U.S.A. 42, 703.Google Scholar
Carroll, E. J. & Schalm, O. W. (1962). J. Dairy Sci. 45, 1094.Google Scholar
Christ, W. (1962). Dt. tierärztl. Wschr. 69, 108.Google Scholar
Dounce, A. L. (1955). The Nucleic Acids, vol. II (eds. Chargaff, and Davidson, ), p. 93.New York: Academic Press.Google Scholar
Dounce, A. L. & Monty, K. J. (1955). J. biophys. biochem. Cytol. 1, 155.CrossRefGoogle Scholar
McManus, J. F. A. & Mowry, R. W. (1960). Staining Methods, Histologic and Histochemical. New York: Hoeber.Google Scholar
Nageswararao, G., Blobel, H. & Derbyshire, J. B. (1965). J. Dairy Sci. 48, 1290.Google Scholar
Nageswararao, G. & Derbyshire, J. B. (1969). J. Dairy Sci. 52 (in the Press).Google Scholar
Postle, D. S. & Blobel, H. (1965). Am. J. vet. Res. 26, 90.Google Scholar
Schalm, O. W. & Noorlander, D. O. (1957). J. Am. vet. med. Ass. 130, 199.Google Scholar
Scruggs, R. L. & Ross, P. D. (1964). Biopolymers 2, 593.CrossRefGoogle Scholar